Control of gasoline electric power systems



CONTROL OF GASOLINE ELECTRIC POWER SYSTEMS Filed OC;.l2, 1926 ATTORNEYS.

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Patented Mar. 13, 1928.

UNiTEDg STATES 1,662,092 PATENT OFFICE.

OLIVER F. WARHUS, ALBANY, NEWKYORK, ASSIGNOR TO VERSARE CORPORATION,

i A. CORPORATION 0F NEW YORK.

CONTROL OF GASOLINE ELECTRIC POWER SYSTEMS.

Application led. October 12, 1926. Serial No. 1413150.

tric generator which furnishes current to one or more electric motors' geared to the traction wheels. lln the operation. of such vehicles it is etten desirable to stop the vehicle without stopping the internal combustion engine, the engine being permitted to idle. Even when the engine is idling there is a small amount ot current being delivered.

to the motor and therefore there is always possibility ot the vehicle moving or creeping. This could he prevented by a separat-e controlling device to make sure that sufficient current will not be delivered to the motor to operate it when the engine is idling, hut such an arrangement would not be :toolproo't and would require an additional operation to he performed hy the operator upon stopping the vehicle.

According to this invention there is provided a tool-proof combined actuating device vfor controlling the throttle valve of the engine' carhuretor and for controlling the generator so that when the actuating device is in its normal position the engine is pen mitted to idle7 but the current supplied by the generator to the motor will be cut oila or least reduced to so small anamount thatv there is no danger ot the vehicle creeping.. wvlhen the actuating device is operated it first renders the generator capable of tur nishing sutlicient current to the motor to propel it and thereafter it actuates the throttle valve otD the engine carburetor to speed up the engine. l/V hen the control device is used on a vehicle it may be in the iorm oi an accelerator pedal having an electric switch associated therewith connected in the held circuit oi the generator. When the accelerator pedal is in its normal raised position the contactsare open and although the engine ils permitted to idle the generator will he incapable of furnishing enough cur-- rent to the motor to operate it. When the accelerator pedal is depressed it first closes the electric switch to place the generator in condition for furnishing enough current to the motor, and thereafter it actuates the throttle valve to speed up the engine. l/Vhen pressure upon the accelerator pedal is released the reverse operation takes place, i. e. the engine is first slowed down to its idling speed and when the accelerator pedal is allowed to return all the way to its normal position the electric switch is opened to break the generator iield circuit thus insuring that while the engine is idling the vehicle will not creep.

rlhe accompanying drawings illustrate a gasoline-electric propulsion or driving system for a vehicle which is controlled in accordance with the invent-ion and also illustrate several different forms of the controller per se.

lin the drawings:

liig. l is a diagrammatic view of a sinr wheel vehicle having a gasoline-electric drive controlled in accordance with the invention; s

lFig. 2 is a vertical section or" one form of controlling device;

Fig. 3 is a vertical section out a modilied form of controlling device; and

Fig. l is a horizontal section taken on the line Ll-l oi Fig. 3 lout showing the switch i'n its closed position.

Fig. l shows the invention as applied to a sin wheel vehicle having two individual motors tor driving the two rear axles. However, the invention is equally applicable to a gasoline-electric drive of any vehicle regardless of the number of motors employed. For instance, the vehicle may have only tour wheels with one motor 'for driving the two rear wheels or the vehicle may be an eight wheel vehicle in which the body is mounted upon front and rear bogie trucks each of which is provided with a driving motor. The type of vehicle shown in Fig. 1 comprises a bodyl mounted upon 'front steering wheels 2 and four rear wheels indicated at 1l.. Each pair of rear wheels is mounted upon a dead axle 6 and is driven from a live axle 7 geared to a propeller shaft 8 through differential gearing 9. Each propeller shaft 8 is 4driven by an electric motor l0. The connections from leach motor to the corresponding ltraction Wheels are shown more or less diagrammatlcally as they do not form a part of the present invention. For the present purpose it is sufficient to note that there is at least one electric motor that drives at least one pair of rear Wheels. rll`he driving-system for the vehicle also includes an electric generator represented diagrammatically at 1l Which i's mechanically connected with an` internal combustion engine represented diagrammatically at l2. 'llhe tWo electric motors 10 Jare connected in parallel and are electrically connected with the generator by the conductors 13. lin the present instance the generator is of that type Whose main field Winding 11i is augmented by a separate so-called t1ckler field Winding 15 energized by means of a storage battery 16.l 'llhe main kfield Winding ltmay be controlled by means of a controller represented diagrammatically at 17 so as to vary the output ofthe generator. 'llhc separately excited tickler field Winding 15 has the usual function of increasing the output of the generator for slow speeds and of causing the generator output to build up` in quick response to an increase in speed. However, the presence ot the separately ercited tickler eld makes it possible for the generator, even When the engine is idling, to deliver enough current to the motors to operate them and it is therefore desirable to break the circuit of the field 15 when the engine is idling. When the engine is idling the main field 14., even vvhenthe controller l-'Zgis in. its maximum output position, will not'cause the generator to furnish enough current to the motors to operate them and therefore it is not necessary to break the circuit of the main field lallhough this can be done if desired. Likewise, if' the generator has only one field Winding its circuit may be broken' to render the generator entirely ineffective; f y

The circuitof 'the tickler field 15 is controlled from the accelerator pedal which opl crates the throttley valve lof the engine car,-

buretor. The accelerator pedaland the instrumentalities associated with it may comprise acasing 17, (Fig. 2) in the bottom of which there is slidingly mounted alf-rod 18 carrying at itsupper end an electric conftact 1.9. The cover 20 of the casing' 17 slidingly carries an actuating rod 21 having a knob or the like 22fconveniently located near the drivers seat sothat ismay be actuated by his foot. The lower. end of the actuating rod 21 is providedvvitha second electric contact 23. The actuatingrod 21 is yieldingly held in its normal raised position by means of a coiled spring 24 positioned bevtween a shoulder 25 on the casing 17 and a cup shaped member 26 carried byl the rod 21. The contacts 19-and 23 are connected by means yof leads 27 and 28 respectively to ler field 15 as'shovvn in Fig. 1. The rod 18 f is connected with the throttle valve 29 of the engine carburetor 30 through` a system of links and levers diagrammatically represented at 31 in Fig. l. lin the normal positions o't the actuating rod 21 and the movable rod 18 the contacts 19 and 23 are spaced apart and therefore the circuit of the tickler vfield is open. lin thenormal position of the parts the throttle valve 29 permits the engine to idle. W' hen the operator depresses the actuating rod 21 the contacts 19 and 23 are first closedthereby completing the circuit ot the tickler field 15 .and placing the generator in condition to furnish sufficient current to the motors to operate them. F urther movement of the rod 21 will depress the rod 13 and. this will serve to open the throttle valveof the carburetor and speed up the engine. The speed of the engine may be controlled in the usual Way by varying the pressure upon the actuating rod 21.- Vlhis Will vary the speed of the generator and consequently vary the amount of current suppliedto the motors so that any amount of desired power may be obtainedl from the generator to suit the traffic demand. When the operator reduces the pressure on the knob 22 toalmost the minimum, or when the operators foot is removed from the knob 22, the contacts 19v and 23 will separate thereby breaking the circuit of the tickler field 15 vvhile still permitting the engine to idle.l 0f course the 'operator may stop the engine in the usual `Way if 'he desires by breaking the ignitit/)ncircuit,v but ,ordinarily in making short stops the operator Willv permit the engine to continue idling. During these stops there should be no danger of the generator furnishing enough current to the motors to operate them and this result is ini sured by' the breaking of the tickler field 15. rlhe device is entirely fool-proof inasmuch as. the circuit of the tickler field will always be broken whenever the operator-stoot is -removed from the acceleratory pedal and no dditional operation is( necessary on his partto' v render the generator ineffective as would be the case if were necessary for him' to op-i Y because it is not calledjupon to `furnish current' while theengine is idling.l` Fig. .3 shoyvs a modified form of' control devlce 1n which the actuating rod 2l actu-y ates the rod 18 only after it has moved far. 125

enough to bring a Shoulder 32 ontthe rod 21 into engagement .with a shoulder 33 on the rod 18.` The actuating rod 2l is yieldmgly held in its raised position by means of a coil spring 24: interposed-'between a collarl 1 34 on the actuating rod 21 and a stationary collar 35. When the actuating rod 21 is depressed and before the shoulder 32 comes in Vcontact with the shoulder 33 a roller 36 mounted on the collar 34 depresses an arm 37 associated with a switch 38 so as to move the switch to its closed position against the action of a biasing spring 39. The switch 38 carries two contacts 4() and 41 (Fig. 4) which in the closed position of the switch make engagement with two stationary contacts 42 and 43 mounted in the wall of the controller casing, but insulated therefrom. The binding posts 44 and 45 of the contacts 42 and 43 are connected in the circuit of the tickler field winding 15 Aso that when the switch is closed the contacts 42 and 43 will be bridged and thereby complete the circuit through the tickler field Winding. The arrangement of parts is such that when the actuating rod 21 is actuated the switch just described `will be quickly closed and further movement of the rod 2l will lbring the shoulder 32 into engagementwith the shoulder 33 and thereafter the rod 18 Will be actuated to vary the position ofthe throttle valve, it being understood that this rod is connected With the throttle valve of the carburetor in the same manner as the rod 18 of Fig. 2. The speed of the engine may be varied by varying the pressure upon the knob 22 of the actuating rod 21 during which time the switch will be held closed but when pressure is reduced to a minimum on the knob 22 or when the operators foot is moved altogether fioin this knob the engine is vslowed down to idling speed and then the switch will open to break the circuit of the tickler field Winding 15.

In both forms of the controller illustrated in the drawings only a veiy slight pressure is required to complete the circuit of the field winding of the generator because the distance between the contacts 19 and 23 in the ease of Fig. 2 and between the shoulders 32 and 33 in the case of Fig. 3 is quite small in practice, 'one-quarter of an inch having been found suicient for the purpose.

It will non7 be seen that the invention is of particular value in gasoline electric driving systems for vehicles as it positively insures that the vehicle will not creep when the engine is idling. However, the invention may be useful in any gasoline electric power system regardless of whether or not it is used as a propulsion system for vehicles. Moreover, the controlling device may be useful in other relations and systems of other types. For instance, the controller may be useful for breaking any electric circuit after the speed of an internal combustion engine or other l'device has been tlirottled down and for re-establishing the circuit before increasing the speed of the engine or other device. The details of construction of the controller itself are important only so far as the novelty of the controller is concerned. So far as the entire system is concerned the minor details of the controller are unimportant so long as one device controls the speed of the engine and also renders the generator incapable of furnishing enough current to the motor 'to operate it when the engine is idling.

I claim:

1. A controlling device for controlling an i.

being arranged to be closed by operation of the'actuating device before the actuating device operates said movable member. y

2. A control device comprising a movable member adapted to be connected with a device to be controlled, a movable actuating device for saidm'ember having an initial movement independent of said member before it operates the same, an electric switch associated with said control device having contacts arranged to be open in the normal position ofsaid actuating device and closed upon actuatioiof said device before it operates said member.

3. A control devicefcoinprising a movable member adapted to be connected with a device to be controlled, a movable actuating devicefoa; said member having an initial movement'independent of said member before it operates the same, an electric switch associated with said control device and which is normally openI .in the normal position of the actuating device and means operated by Said actuating device for closing the switch before saidmember is operated by the actuating device.

4. A combined accelerator pedal and contactor for motor vehicles which have an interiial combustion engine and. an electric circuit to ,be controlled, comprising a movable member adapted to be connected with tli-e throttle valve of the engine, a movable foot pedal for actuating said member having an initial movement independent of said member before it actuates it., and an electric switch having contacts arranged to be closed by operation of said foot pedal before the foot pedal operates said movable member.

In testimony whereof I afiix my'signature.

OLIVER F. WAR-HUS. 

